To make things easier, this page displays the logos and the symbols beside the name of the cryptocurrency – it is therefore impossible to make a mistake when looking at the numbers. The logos, names, and symbols appear in the first, second and third column, respectively. The names and symbols of the listed cryptocurrencies are actually links. Clicking on these links a new page with individual data about the chosen coin will be displayed, though it might take some time for the data to load.
Bitcoin is a digital currency, sometimes referred to as a cryptocurrency, best known as the world's first truly decentralized digital currency. Bitcoin is traded on a peer-to-peer basis with a distributed ledger called the Blockchain, and the Bitcoin exchange rate to the US Dollar and other major currencies is determined by supply and demand as with other global exchange rates. The traded value of Bitcoin has proven volatile through various booms and busts in demand. Ultimately, however, many see Bitcoin as a store of value against government-backed fiat currencies.
^ "Millionaire (n and adj)" (available online to subscribers but also available in print). Oxford English Dictionary. Retrieved 20 July 2008. 1816 BYRON Let. 23 June (1976) V. 80 He is still worth at least 50-000 pds{em}being what is called here [sc. Evian] a ‘Millionaire’ that is in Francs & such Lilliputian coinage. 1826 B. DISRAELI Vivian Grey I. ix, Were I the son of a Millionaire, or a noble, I might have all.
Wallets and similar software technically handle all bitcoins as equivalent, establishing the basic level of fungibility. Researchers have pointed out that the history of each bitcoin is registered and publicly available in the blockchain ledger, and that some users may refuse to accept bitcoins coming from controversial transactions, which would harm bitcoin's fungibility.[123] For example, in 2012, Mt. Gox froze accounts of users who deposited bitcoins that were known to have just been stolen.[124]
Central to the appeal and function of Bitcoin is the blockchain technology it uses to store an online ledger of all the transactions that have ever been conducted using bitcoins, providing a data structure for this ledger that is exposed to a limited threat from hackers and can be copied across all computers running Bitcoin software. Every new block generated must be verified by the ledgers of each user on the market, making it almost impossible to forge transaction histories. Many experts see this blockchain as having important uses in technologies such as online voting and crowdfunding, and major financial institutions such as JPMorgan Chase see potential in cryptocurrencies to lower transaction costs by making payment processing more efficient. However, because cryptocurrencies are virtual and do not have a central repository, a digital cryptocurrency balance can be wiped out by a computer crash if a backup copy of the holdings does not exist, or if somebody simply loses their private keys.
Bloomberg reported that the largest 17 crypto merchant-processing services handled $69 million in June 2018, down from $411 million in September 2017. Bitcoin is "not actually usable" for retail transactions because of high costs and the inability to process chargebacks, according to Nicholas Weaver, a researcher quoted by Bloomberg. High price volatility and transaction fees make paying for small retail purchases with bitcoin impractical, according to economist Kim Grauer. However, bitcoin continues to be used for large-item purchases on sites such as, and for cross-border payments to freelancers and other vendors.[141]
1) Irreversible: After confirmation, a transaction can‘t be reversed. By nobody. And nobody means nobody. Not you, not your bank, not the president of the United States, not Satoshi, not your miner. Nobody. If you send money, you send it. Period. No one can help you, if you sent your funds to a scammer or if a hacker stole them from your computer. There is no safety net.
The overwhelming majority of bitcoin transactions take place on a cryptocurrency exchange, rather than being used in transactions with merchants.[138] Delays processing payments through the blockchain of about ten minutes make bitcoin use very difficult in a retail setting. Prices are not usually quoted in units of bitcoin and many trades involve one, or sometimes two, conversions into conventional currencies.[32] Merchants that do accept bitcoin payments may use payment service providers to perform the conversions.[139]
^ Beikverdi, A.; Song, J. (June 2015). Trend of centralization in Bitcoin's distributed network. 2015 IEEE/ACIS 16th International Conference on Software Engineering, Artificial Intelligence, Networking and Parallel/Distributed Computing (SNPD). pp. 1–6. doi:10.1109/SNPD.2015.7176229. ISBN 978-1-4799-8676-7. Archived from the original on 26 January 2018.
Most cryptocurrencies are designed to gradually decrease production of that currency, placing a cap on the total amount of that currency that will ever be in circulation.[25] Compared with ordinary currencies held by financial institutions or kept as cash on hand, cryptocurrencies can be more difficult for seizure by law enforcement.[1] This difficulty is derived from leveraging cryptographic technologies.
As of May 2018, over 1,800 cryptocurrency specifications existed.[24] Within a cryptocurrency system, the safety, integrity and balance of ledgers is maintained by a community of mutually distrustful parties referred to as miners: who use their computers to help validate and timestamp transactions, adding them to the ledger in accordance with a particular timestamping scheme.[14]

The legal status of cryptocurrencies varies substantially from country to country and is still undefined or changing in many of them. While some countries have explicitly allowed their use and trade,[51] others have banned or restricted it. According to the Library of Congress, an "absolute ban" on trading or using cryptocurrencies applies in eight countries: Algeria, Bolivia, Egypt, Iraq, Morocco, Nepal, Pakistan, and the United Arab Emirates. An "implicit ban" applies in another 15 countries, which include Bahrain, Bangladesh, China, Colombia, the Dominican Republic, Indonesia, Iran, Kuwait, Lesotho, Lithuania, Macau, Oman, Qatar, Saudi Arabia and Taiwan.[52] In the United States and Canada, state and provincial securities regulators, coordinated through the North American Securities Administrators Association, are investigating "bitcoin scams" and ICOs in 40 jurisdictions.[53]
Reuben Rosenthall had made his millions on the diamond fields of South Africa, and had come home to enjoy them according to his lights; how he went to work will scarcely be forgotten by any reader of the halfpenny evening papers, which revelled in endless anecdotes of his original indigence and present prodigality, varied with interesting particulars of the extraordinary establishment which the millionaire set up in St.
The term altcoin has various similar definitions. Stephanie Yang of The Wall Street Journal defined altcoins as "alternative digital currencies,"[20] while Paul Vigna, also of The Wall Street Journal, described altcoins as alternative versions of bitcoin.[21] Aaron Hankins of the MarketWatch refers to any cryptocurrencies other than bitcoin as altcoins.[22]
^ Chan, Edwin. "China Plans to Ban Cryptocurrency Mining in Renewed Clampdown". Retrieved 10 April 2019. While China was once home to about 70 percent of Bitcoin mining and 90 percent of trades, authorities have waged a nearly two-year campaign to shrink the crypto industry amid concerns over speculative bubbles, fraud and wasteful energy consumption.